Circuit breaker



Nov. 28, 1939. M. L. JEFFREY CIRCUIT BREAKER Filed March 13, 1939 INVENT OR. MAX LZEFFREY AT' i'ORNEYS Patented Nov. 28, 1939 UNITED STATESPATENT OFFICE 2,181,829 omom'r BREAKER Ohio Application March 13, 1939,Serial No. 261,411

5, Claims.

This invention relates to circuit breakers, and more particularly to animproved operating mechanism for circuit breakers.

It is common practice in automatic machinery,

to provide switches so disposed that reciprocating or rotating parts ofthe machine actuate certain switches to initiate movement in some otherpart of the machine, or for indicating that a movement has beencompleted. Inasmuch as these switches are operated by various parts ofdifferent types of machines, it has necessitated to a considerableextent individual design for each machine.

It is one of the objects of this invention to provide a switch mechanismwhich is versatile in its applications one particular mechanism beingreadily adapted to various types of machines. It is a further object toprovide a switch mechanism where a number of the switches may be gangedand operated by a single cam shaft or timing mechanism.

Still another object of the invention resides in providing a mechanismfor operatinga so-called micro-switch where, although the switch may beactuated by different mechanisms, the microswitch is operated within thelimits of travel essential to long life and is not damaged byover-travel or greater pressure ordinarily caused by the differentapplications where the device is used.

Still other advantages of the invention and the invention itself, willbecome apparent from the following description of some embodiments,which embodiments are illustrated by the accompanying drawing and whichdescription forms a part of this specification.

In the drawing:

Fig. 1 isa sectional view of the mechanism of my invention in elevation;

Fig. 2 is a section on the line 22 of Fig. 1;

Fig. 3 is a view partly in elevation and partly in section of one typeof operating mechanism; and

Fig. 4 is an elevational view of another type of operating mechanism.

Referring now to the drawing throughout which like parts have beendesignated by like reference characters.

The device generally comprises a rectangular housing adapted to besecured or mounted on a machine adjacent a reciprocating or rotatingpart which is to operate the switch. .In the housing there is disposed amicro-switch which may be of the type disclosed in Patent No. 1,960,020,the

micro-switch per se being no part of the present invention other than asis claimed in the combination. A lever mechanism is supported in thehousing for actuating the micro-switch and it in turn is operated by acam or plunger having operating parts extending out of the housing and 5adapted to be connected to the reciprocating and/or rotating part of themachine which is to operate the switch.

More specifically the housing comprises a metallic box I which may becast in rectangular 10 form with two open sides which are adapted to beclosed by plates 2 and 3 held onto the box by screws 4. A sheet of fiberinsulation 5 may be provided and is particularly desirable on thesidewhere the conductor wires connect with the 15 micro-switch which isindicated at 6 to the leads 8.

The micro-switch is held in a fixed position in the housing bysupporting pins 9 which extend through the base of the switch andthrough the 20 walls l0 and H of the housing. The pins 9 may be threadedadjacent their heads and screwed into threads in the wall to hold thesame in position.

The operating mechanism for the micro-switch 25 comprises a lever i2pivotally disposed on a pin I3 which is journalled in the walls I!) andH, the lever being provided with an enlarged boss M for the reception ofsaid pin. A substantially Z-shaped leaf spring I5 is secured to thelever 30 by rivets 5, with the free end I! of the spring in contact withthe operating pin l8 of the microswitch 6. One end of the lever i2 isprovided with an enlarged bifurcated portion IS in which a roller 2!! isrotatably supported on a pin 2|. 35 The other end 22 of the lever, whichis relatively short, is provided with a threaded aperture and carries aset screw or stud 23 which may be held in adjusted position in theleverby a lock nut 24. The end 25 of the screw 23 contacts the spring I5intermediate its ends and provides a means for adjusting angulardisplacement, and hence the tension, of said spring relative to thelever. Various means may be provided for moving the lever l2 bycontacting with the roller 20, one of 45 the preferred forms including ashaft 26 rotatably journalled in bearings 21 disposed in bosses 28 ofthe walls I0 and H of the housing. The shaft. carries a cam 29 uponwhich the roller 20 rides. One end of the shaft 26 extends exteriorly of5 the housing and carries on its end a lever 30. The lever is adapted tobe engaged by the reciprocating part of the machine by which itoperates. Obviously the shaft 26 can either rotate or rec procate andthe lever 30 could be replaced by a 55 gear, or the shaft 26 can bedirectly connected by a universal coupling to any rotating part so' longas the desired switch timing is attained.

In operation the micro-switch usually takes 14 ounces pressure on thepin end to operate the same. The set screw 23 is adjusted so that themaximum pressure upon rotation of the cam 29 applied to the pin I8 is 20ounces. When the cam 29 is rotated the high spot 29' on the cam urgesthe roller 20 and end of the lever l2 upward as viewed in Fig. 1, whichcauses the lever to be rotated about its pivot and transmit pressurethrough the end 22 and screw 23 to the midportion of the spring i andthence by the end I I of the spring to the operating pin I8v of themicro-switch. It will be clear that regardless of how much movement isapplied to the outside lever 30 or how fast the cam is rotated, thepressure applied to the micro-switch never exceeds 20 ounces because ofthe adjustment of the set screw 23 and thus no unusual stresses areplaced on the switch mechanism.

As best shown in Fig. 3, I have illustrated another type of operatingmechanism for the lever l2 which includes a housing 40 secured to theend of the casing l by screws 4|. The housing is provided with alongitudinal bore 42 in which is disposed a piston 43 having an exterioroperating head 44. The end of the piston is provided with a reduced stem45'and carries on its end inside of the housing a cam 46 which is pinnedto the stem by a taper pin 41. A helical spring 48 is disposed about thestem 45 having one end engaging against the shoulder 49 of the pistonand the other end bearing against the re-entrant wall 50 of the housing42 to urge the piston and operating head 44 to its outward position. Thecam 46 rests against the roller 20 and when pushed inward by pressure onthe head 44, causes the roller to ride up on the surface 5| and move theroller to the left as shown in the drawing. When pressure on the head 44is relieved, the spring 44 returns the piston toits original position.The mechanism otherwise is the same as shown in Fig. 1.

Although I have described but one microswitch being operated by onelever and one cam, as previously stated, it would be quite within thepurview of this invention to provide a bank of such switches, levers andcams operable from a single cam shaft 26, the timing; of the switchesbeing dependent upon the position of the high spots 29' of the cams. Abank of such switches could also be operated exteriorly by theindividual mechanism such as shown in Fig. 3. In either event themechanisms for transmitting a predetermined pressure to the contactorplungers l8 would be as shown and described.

It will thus be seen that in the device shown in Figs. 1, 2 and 4, nomatter what instrumentality is used to rotate the cam shaft, or whetherthe movement be large or small, the pressure for operating 'themicro-switch does not exceed a predetermined maximum and thus result indamage to the delicate interior mechanism of the micro-switch.

Having thus described my invention and' some embodiments thereof, I amaware that numerous and extensivezdepartures may be made therefrom.

by those versed in the art in view of the disclosure herein, and it isnot my intention to limit my invention to the precise embodiment shownotzllzer than as is indicated in the appended claimsclaim: 4

1. A switch operating mechanism including a I spring, a cam inconnection with the leverand adapted'to be moved from without thehousing.

'2. In a device of the class described, a housing, a lever comprising abody pivotally supported by the housing, a roller on one end of saidlever, a

cam for moving said roller, a leaf spring secured to said leverintermediate its pivot and said roller and extending beyond the free endof said lever, adjusting means for positioning said spring relative tothe lever comprising a screw threaded through the free end of said leverand energizing the face of said spring, and a lock nut for locking saidscrew in adjusted position, and a switch adapted to be actuated by saidspring.

3. In a device of the class described, a housing, a contactordisposed-within said housing, means for operating said contactorcomprising a lever pivotally supported in the housing,a spring supportedby said lever and extending in prolongation'thereof with the endoperably engaging the contactor, and means to adjustably position saidspring supported by said lever including a threaded stud extendingtherethrough and engaging said spring and adapted to change the angularposition of said spring relative to said lever, and locking means forsaid stud, and means for moving said lever comprising a cam rotatablyjournalled in said housing and having an axial extension disposedoutside of the housing, and a roller carried by the lever and held incontact with said cam by said spring. 4. In a device of the classdescribed, a housing, a switch disposed in the housing for controllingan electrical circuit, means for operating said switch including a leverpivotally supported in said housing and carrying a spring extension onone end, means to vary the position of said spring comprising a screwthreaded through-the lever and engaging said spring to vary the angularrelation between the spring and lever, and locking means for fixing theposition of said screw, means having an operating plunger, means foroperating -said contactor comprising a lever pivotally supported on apin journalled in the walls of said housing, a Z-shaped spring carriedby said lever and extending beyond an end thereof with the free end inengagement with said plunger, and means to adjustably position saidspring supported by said lever comprising a threaded stud extendingthrough the lever engaging said spring intermediate its end and itspoint of attachment to said lever, and adapted to adjust the angularposition of said spring relative to said lever, and locking means forsaid stud, the free end of said lever being bifurcated and a rollerpivotally supported thereby, a cam journalled in'said housing and inengagement with said roller and having a portion disposed outside of thehousing adapted for movement from an external source.

- MAX L. JEFFREY.

